Final answer:
Without a specific graph to refer to, we cannot determine which equation matches the blue line. However, all options presented represent linear equations in the form y = mx + b.
Step-by-step explanation:
To determine which of the given options is an equation for the blue line, we must understand the general form of a linear equation, which can be represented as y = mx + b, where m is the slope and b is the y-intercept of the line. From the information provided, we understand that every option presented in the multiple-choice question represents a linear equation because they can be rearranged into the general form of a linear equation, as exemplified by y = -3x, y = 0.2 + 0.74x, and y = -9.4 - 2x. However, without a specific graph to refer to in the student's question, we cannot determine accurately which equation corresponds to the blue line. Therefore, the response to this specific question is 5.) None of the above, considering none of the equations can be confidently chosen without seeing the actual blue line on a graph.